Szmuszkovicz U.S. Pat. No. 4,145,435 discloses some cis- and trans-N-(2-aminocycloaliphatic)-2-arylacetamide derivative compounds, e.g., N-[2-(N',N'dimethylamino)cyclohexyl]-N-methyl-2-(4-bromophenyl)-acet amide and trans-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-2-(3,4-dichlorophenyl)acet amide, which have potent analgesic activity; the preferred compounds thereof have, in addition, only low to moderate apparent physical dependence liability compared to morphine and methadone. That Szmuszkovicz '435 patent also describes some prior art patent and publication background that may be of interest herein also.
Also, Szmuszkovicz U.S. Pat. No. 4,098,904 discloses some cis- and trans-N-(2-aminocycloaliphatic)benzamide compounds, e.g., N-methyl-N-[2-aminocycloaliphatic]benzamide compounds, e.g., N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-3,4-dichlorobenzamide, which have potent analgesic activity, making them useful for relieving pain in warm blooded animals. That '904 patent also discloses background patents and publications which may be of interest herein.
Lednicer U.S. Pat. No. 4,212,878, discloses some N-[(1-amino-4-(mono- or di-oxygen-group-substituted)cyclohexyl)methyl]benzeneacetamide derivatives, e.g., 2-(3,4-dichlorophenyl)-N-[[8-(1-pyrrolidinyl)-1,4-dioxaspiro[4.5]dec-8-yl] -methyl]acetamide, which also have analgesic drug properties with lower physical dependence liability characteristics than morphine or methadone. That Lednicer patent also refers to what is now Lednicer U.S. Pat. No. 4,065,573 which discloses some 4-amino-4-phenylcyclo-hexanone ketal compounds, e.g., 4-(m-hydroxyphenyl)-4-(dimethylamino)-cyclohexanone ethylene ketal and 4-(m-hydroxyphenyl)-4(n-butylmethyl-amino)cyclohexanone ethylene ketal, which are useful for relieving pain in animals, some of which compounds exhibit narcotic antagonist ractivity.
Other references are listed in the accompanying prior art statement.
Representative compounds of some of the above types have been or are being studied in advanced animal drug studies. Some concern has been expressed about possible dysphoric side effects of such compounds when used as analgesic drugs. Those skilled in the art continue to search for new and more advantageous analgesic compounds.